Conventional electrical components that permitted one to vary resistance, inductance, and/or capacitance under electrical control typically have somewhat limited component values available and are not compatible with being located in high fields (e.g., the fields of 1 tesla or more that are typically found in high-energy physics experiments such as the $9 billion Large Hadron Collider that has been 20 years in making and is still being modified to be able to operate).
Low-power circuits can use varactors (electrically variable capacitors), field-effect transistors (used as variable gain elements or variable resistors) and like components that are directly electrically-adjustable, for use in adjusting frequency, impedance or other circuit characteristics and parameters, however such components are often unsuitable or inoperative in high fields.
U.S. Pat. No. 6,495,069 issued Dec. 17, 2002 to Lussey et al. titled “Polymer composition,” is incorporated herein by reference. Lussey et al. describe a polymer composition comprises at least one substantially non-conductive polymer and at least one electrically conductive filler and in the form of granules. Their elastomer material was proposed for devices for controlling or switching electric current, to avoid or limit disadvantages such as the generation of transients and sparks which are associated with the actuation of conventional mechanical switches. They described an electrical conductor composite providing conduction when subjected to mechanical stress or electrostatic charge but electrically insulating when quiescent comprising a granular composition each granule of which comprises at least one substantially non-conductive polymer and at least one electrically conductive filler and is electrically insulating when quiescent but conductive when subjected to mechanical stress. They did not propose a means for electrically activating such switches.
There is a long-felt need for components having resistance, inductance, and/or capacitance values that are variable under electrical control and are compatible with being operated in extremely high electromagnetic fields.